Atlanta broadcaster Ted Turner contacted wealthy investors earlier this month in an effort to raise $2.5 billion in cash that could be used to increase his takeover bid for CBS Inc., sources said yesterday.

Meanwhile, Turner confirmed yesterday that he recently had dinner at the New York Yacht Club with wealthy Saudi Arabian businessman Adnan Khashoggi. However, Turner denied that the purpose of the meeting was to ask for funds for his takeover bid.

Turner, who is scheduled to discuss his bid for CBS today before the Senate Commerce Committee, said the meeting was initiated by Khashoggi. Turner said Khashoggi, who is believed to be one of the world's richest men, was interested in representing him in the Middle East when Turner begins distributing Cable News Network in the region.

Sources said that Khashoggi has done considerable business with E. F. Hutton, the investment firm that is representing Turner in his takeover bid. But Turner said the dinner with Khashoggi was not arranged by Hutton.

"The whole thing was initiated by Khashoggi," said George Vandeman, a partner with the New York law firm of Latham & Watkins, which is advising Turner on his takeover bid. "It was triggered by the announcement that we are taking Cable News Network to Europe. Khashoggi, through his people, requested a meeting with Turner to talk about Khashoggi distributing CNN in the Middle East."

Sources said that earlier this month, Turner offered wealthy investors 15 percent notes; warrants to purchase up to 40 percent of the stock in CBS if the company is acquired, and the chance to make the first bid on CBS properties that are divested as part of the takeover, if they would give Turner the cash he needs to make his takeover offer more attractive. "There were no takers," one source said.

" . . . Turner had dinner with Khashoggi recently, and Turner is only working on one thing these days the CBS takeover attempt ," the source said. "Khashoggi has the one thing Turner needs, cash."